The effect of retinal S-antigen-specific monoclonal antibody therapy on experimental autoimmune uveoretinitis (EAU) and experimental autoimmune pinealitis (EAP).

We induced an autoimmune uveitis and pinealitis in Lewis rats by inoculating them with bovine S-antigen. This type of uveitis forms a useful experimental model of human chronic intra-ocular inflammation. Induction of experimental autoimmune uveitis (EAU) but not of experimental autoimmune pinealitis (EAP) could be prevented by the administration of S-antigen-specific monoclonal antibody simultaneously with the S-antigen. Inhibition of EAU was associated with significantly raised levels of anti-S antibodies during the first 2 weeks post-immunisation. Immunocytochemical staining for lymphocyte subsets, monocytes and macrophages showed that eyes of monoclonal antibody treated animals contained no immunocompetent inflammatory cells unless they also had clinical signs of inflammation. In contrast, the inflammatory exudate in the pineal glands of both treated and untreated animals contained equal numbers of infiltrating lymphocytes and monocytes in the same relative proportions. These results indicate that the inhibitory effect of the monoclonal antibody S2.4.C5 may be directed towards the effector arm of the immune-mediated cytotoxic response.